1. Field of the Invention
The present invention relates to an antenna module installed on an electronic apparatus having a wireless communication function, and more particularly to an antenna module, which minimizes a space, in an electronic apparatus set, occupied thereby, improves a degree of freedom of the installation structure thereof to increase the space utilization of the set, and achieves miniaturization and multi-functionality of electronic apparatuses, and an electronic apparatus having the antenna module.
2. Description of the Related Art
In order to meet the recent development of semiconductor and communication technique, electronic apparatuses having a wireless communication function for improving mobility and portability thereof by users (hereinafter, referred to “wireless electronic apparatuses”) have generally been used. A cellular phone is a good example of a wireless electronic apparatus. In order to satisfy user's requirements to the portability, wireless electronic apparatuses have been gradually developed into increasingly light-weight and miniature devices.
Further, in order to satisfy user's requirements to the convenience in possession so that a single apparatus has at least two functions, the wireless electronic apparatuses have been multi-functionalized so as to include at least one function selected from MP3, camera, credit card, and wireless contact-type traffic card functions.
Accordingly, the miniaturization of components of the wireless electronic apparatuses has been researched. The above research is applied to an antenna for transmitting and receiving wireless signals. The conventional wireless electronic apparatuses generally use internal antennas so as to reduce the size of products. The internal antennas include a microstrip patch antenna, a flat inverted F-type antenna, and a chip antenna.
The microstrip patch antenna is embodied by a microstrip patch printed on a printed circuit board. In the chip antenna, multi-layered radiation patterns having various shapes including a spiral shape are formed in a dielectric block, and are electrically connected, thereby functioning as an antenna having a route of current corresponding to a designated frequency.
As shown in FIG. 1, an inverted F-type antenna comprises a radiation patch 11 formed at a designated height from the upper surface of a PCB (printed circuit board) 10, a feeder line 12, for applying current, and a ground line 13, which are connected to one edge of the radiation patch 11. The feeder line 12 and the ground line 13 are perpendicular to the radiation patch 11, and bonded to signal and ground patterns on the PCB 10.
The radiation patch 11 may have a rectangular shape. In FIG. 1, in order to expand a transmitting and receiving band and improve antenna characteristics, the radiation patch 11 on a rectangular conductive plane is divided into slits having designated shapes, thereby being deformed to a spiral shape. The radiation patch 11 may be deformed into various shapes. In the inverted F-type antenna of FIG. 1, the radiation patch 11 has two current routes, and receives and transmits frequency signals having wavelengths corresponding to electric lengths of the two current routes.
Here, the feeder and ground lines 12 and 13 of the radiation patch 11 may be supported by a designated dielectric, for example, a ceramic block.
As shown in FIG. 1, the above-described conventional internal antenna requires a peripheral space having a designated size or more, which is not grounded, in order to maintain characteristics thereof, when the internal type antenna is mounted on a wireless electronic apparatus set 10. Accordingly, the conventional internal antenna occupies a space, on the wireless electronic apparatus set, having a size larger than that of the antenna. It is difficult to prepare the corresponding space on wireless electronic apparatuses, which require miniaturization and multi-functionality. If it is possible to decrease the above space, the wireless electronic apparatus can be further miniaturized. Accordingly, it is necessary to decrease the space for installation of the antenna on the wireless electronic apparatus.
Japanese Patent Laid-open No. 2003-87022 discloses an antenna module having a high mounting density. FIG. 2 is a perspective view of the antenna module disclosed by the above Patent. With reference to FIG. 2, the antenna module comprises an antenna element 22, a driving circuit 23 for supplying current to the antenna element 22, and a waveguide 24 extended from one side surface of a PCB 21, on which the driving circuit 23 is installed, for connecting the driving circuit 23 and the antenna element 22. Here, the waveguide 24 is formed on a hard member having flexibility, and is bent so that the antenna element 22 can be three-dimensionally disposed on the PCB 21. In the antenna module having the above constitution, the antenna element 22, the waveguide 24, and the PCB 21 are integrally formed, thereby reducing the number of steps of an assembly process and achieving freedom of disposing wires or components.
When the waveguide 24 is vertically folded to be installed in a wireless electronic apparatus after the above antenna module is manufactured, the impedance of the waveguide 24 of the antenna module is changed, thereby causing signal loss and deteriorating characteristics of the antenna module.
Therefore, there has been developed an antenna module, which requires a small installation space on an electronic apparatus set and has a high freedom of disposition without changing characteristics thereof.